Question

A 58-year-old woman with lung cancer develops hyponatraemia (Na 118 mmol/L) with low serum osmolality and inappropriately elevated urine osmolality and sodium. She is euvolaemic on examination and has mild confusion. The likely diagnosis is syndrome of inappropriate antidiuretic hormone secretion (SIADH). What is the mainstay of initial management in a stable patient?

Accepted Answer

Fluid restriction to 800-1000 mL per day

Answer

Rapid correction with hypertonic saline to normalise sodium within 12 hours

Answer

High-dose loop diuretics alone

Answer

Oral sodium chloride tablets without fluid restriction

Answer

No treatment is required for asymptomatic hyponatraemia

Practice question